The Capcom encyclopedia sounds pretty amazing. I paid about $10 for it, which I thought was a pretty amazing price.
But then I got it and read it. Ten dollars is a fair price, but I would have never paid full price for this after seeing it in person. Pictures are lacking, and each character only gets one page. However, there truly is 30 years worth of characters in this book. Resident Evil, Darkstalkers, Mega Man (with MM from Legends given his own page, which I appreciated), and so on. Some of the pictures aren't even that great, to be honest. Each character get a one page bio, and that's it. I had hoped for something a bit more fulfilling, this is really just fluff you can get from Wikipedia, in some cases, even less.
However, it is a nice casual, coffee table book. If you are interested in Mega Man more than others, I would recommend just getting the Mega Man Complete Works Book:
MM25 Mega Official Complete Works
It's pricier, yes, but an absolute gorgeous book for Mega Man fans.
This is an ok book, but I hope Capcom releases a true encyclopedia with lots of pictures, backstories, and interviews in the future.